Field of Invention
This invention relates generally to the use of a rotating fluid jet to produce a rotating fluid wave in the washing fluid which provides localized fluid motion or agitation for efficient washing. In an illustrated embodiment rotating fluid jets are used to produce rotating fluid waves in a top loading clothes washer.
It is known to use in washing machines different types of liquid flow systems to improve agitation which include the following:
U.S. Pat. No. 3,444,710 discloses a fluid flow agitation system in which an external pump is used to recirculate the fluid with a fluid amplifier to create a pulsating jet flow into the washer and thereby produce a high level of agitation.
U.S. Pat. No. 3,867,821 discloses a modulated recirculation system in which an external centrifugal pump is used with a mechanically modulated nozzle to produce a spatially unsymmetrical field of turbulence which sweeps cyclical around the spin basket.
U.S. Pat. No. 4,744,228 also discloses a recirculating flow system with an external pump to supply a venturi conduit in the bottom of the tub which produces a torroidal flow of fluid in the spin basket.
Numerous disclosures have been made for pumping a portion of the wash fluid with the oscillating agitator to enhance washing action in an automatic washing machine. The most recent are disclosed in U.S. Pat. Nos. 4,420,952: 4,419,870: 4,402,198 and 4,077,239. In these disclosures the oscillating motion of the mechanical agitator is used to obtain pumping so that some of the fluid can be filtered and discharged at the top of the agitator. These disclosures use check valves, flapper valves, positive displacement pumps and ram or inertia forces in various combinations to produce the fluid motion. In these disclosures the main wash fluid agitation is produced by a mechanical oscillating motion agitator as used in conventional washing machines.